Understanding the structural and charge transport property relationships for a variety of merocyanine single-crystals: a bottom up computational investigation
Understanding the structural and charge transport property relationships for a variety of merocyanine single-crystals: a bottom up computational investigation
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DOI：
10.1039/d1tc01511g
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发表时间：
2021-06-16
影响因子：
6.4
通讯作者：
Fazzi, Daniele
中科院分区：
文献类型：
--
作者：
Gildemeister, Nora;Ricci, Gaetano;Fazzi, Daniele
部花青由通过次甲基桥连接的电子供体（D）和受体（A）亚基组成。它们是高极性有机π共轭分子，研究了它们的自组装和光电性质。准确描述它们的结构-性质关系仍然具有挑战性。我们报告了一个全面的分析建模内和分子间的电荷传输参数为库的部花青具有不同的D/A组合和横向取代基。我们发现，约束DFT正确评估单晶中的分子和电子结构。确定了最有效的电荷传输途径，并计算了载流子迁移率。我们分析了大量的单晶体，突出了烷基取代基和浇铸条件的影响，绘制了清晰的结构与电荷传输关系。我们的模型表明，空穴传输最大化时，偶极分子被包装在滑动而不是中心对称对，排列在二维互连架构。计算和实验的单晶电荷迁移率是在很好的协议。
Merocyanines consist of electronic donor (D) and acceptor (A) subunits connected via a methine bridge. They are highly polar organic pi-conjugated molecules investigated for their self-assembly and optoelectronic properties. The accurate description of their structure-property relationships remains challenging. We report a comprehensive analysis modelling intra- and inter-molecular charge transport parameters for a library of merocyanines featuring different D/A combinations and lateral substituents. We found that constrained DFT correctly assesses the molecular and electronic structure in single crystals. The most effective charge transport pathways were identified and charge carrier mobilities were computed. We analyzed a large variety of single crystals highlighting the impact of alkyl substituents and casting conditions, drawing clear structure vs. charge transport relationships. Our modelling suggests that hole transport is maximized when dipolar molecules are packed in slipped not centrosymmetric pairs, arranged in 2D interconnected architectures. Computed and experimental charge mobilities for single crystals are in good agreement.